A common position control apparatus for adjustable motor vehicle steering columns includes a bracket on the vehicle body having parallel legs straddling the steering column and a clamp which squeezes the legs of the bracket against the steering column when a control lever is pivoted to a clamping position. Usually, screw threads or a rotary cam in the control apparatus converts rotation of the control lever to axial separation between jaw elements of the clamp. In clamps having interlocking features such as spline teeth on the jaw elements, smooth adjustment of the position of the steering column requires maximum separation between the interlocking features in a releasing position of the control lever. To that end, some prior apparatuses maximize axial separation between jaw elements of the clamp by means of multiple lead screw threads or by means of rotary cams with steep ramps. A position control apparatus according to this invention is an improvement relative to prior position control apparatuses having either screw threads or rotary cams.